This invention relates generally to magnetic disc drives, and more specifically the invention relates to a magnetic disc drive of the Winchester type having an improved braking device.
As is well known, inadvertent rotation of the disc drive during drive installation or removal can seriously damage the disc and/or drive mechanism. Various devices are known in the prior art for locking the disc drives against rotation. In one design, the disc drive had first to be removed from its case and a locking bar and screw installed. Other locking devices are shown in U.S. Pat. Nos. 4,331,989 to Stephen R. Viskochil and 4,385,333 to Alfred Hasler. These systems are relatively complex.
The present invention provides a brake apparatus of relatively inexpensive structure, and which provides for the automatic locking and unlocking of the disc drive mechanism upon removal and insertion, respectively, of the disc drive in its case.
The invention will be more readily understood by a reading of the detailed description taken in conjunction with the drawing which shows one embodiment of the present invention and in which:
FIG. 1 is a side view of the disc drive brake mechanism of this invention showing the brake in the disc release position.
FIG. 2 is a side view of the disc drive brake mechanism of this invention showing the brake in the disc lock position.
FIG. 3 is a bottom view of the disc drive brake mechanism of this invention.
Referring now to the Figures, there is shown brake mechanism generally designated 1 which comprises a
lever 3 mounted for rotation on
disc drive base 5 by means of
tabs 7 formed in
disc drive base 5.
Pin 9 passes through
tabs 7 and lever 3 such that
lever 3 is free to rotate around the long axis of
pin 9.
Pin 9 is conveniently held in place in
tabs 7 and c clamps 11.
Lever 3 includes
tongue portion 13. Mounted for rotation on
tongue portion 13 is disc brake pad assembly generally designated 15.
Tongue portion 13 is provided with
tabs 17, which rotatably support
pin 19. Brake
pad assembly base 21 has
tabs 23 formed thereon for rotatably mounting on
pin 19.
Pin 19 is held in place in
tabs 17, 23 by
c clamps 25. A
disc brake pad 27, having a
high friction surfac 29, is bonded to brake
pad assembly base 21. A similar
high friction surface 31 is formed on
disc drive hub 33.
An
aperture 35 is formed in
disc drive base 5 to allow passage of the
brake pad assembly 15 through
disc drive base 5 as
lever 3 rotates on
pin 9. Also formed in
disc drive base 5 is
post 37.
Post 37 is provided to keep
spring 39 in place.
Post 37 is long enough to maintain
spring 39 in place but is short enough not to interfere with the rotation of
lever 3 around
pin 9 to the locking position.
Disc drive hub 33 is connected to
disc drive motor 41 shown in broken line in FIGS. 1 and 2 only.
Disc drive hub 33 rotates around axis of
rotation 34. The disc drive is contained in a case, the
base 43 of which is shown in FIGS. 1 and 2.
Case base 43 has one or
more support members 45 formed thereon to support
disc drive base 5.
Referring to FIG. 1, in operation, when the disc drive is in its case,
disc drive base 5 is supported by
support member 45 and by
lever 3. In this position, the weight of the disc drive has compressed
spring 39 causing
lever 3 to rotate clockwise as shown in the drawing, thus moving
disc brake pad 27 out of contact with
disc drive hub 33. This is the normal operational position of the disc drive and disc drive brake 1.
Referring now to FIG. 2, when it is desired to remove the disc drive from its case for maintenance or other reasons, the operator lifts the disc drive out of the case. As the
disc drive base 5 is moved away from
case base 43, the weight of the disc drive is removed from brake mechanism 1. This allows
spring 39 to expand causing rotation of
lever 3 counterclockwise, as shown in FIG. 2, around
pin 9. The counterclockwise movement of
lever 3
forces tongue 13 to move disc
brake pad assembly 15 into contact with
disc drive hub 33. The movement is in a direction parallel to the axis of
rotation 34 of
disc drive hub 33. The strength of
spring 39, combined with the presence of
high friction surfaces 29, 31, firmly locks
disc drive hub 33 in place preventing rotation of the
disc drive hub 33 and thus of the disc drive to which it is attached. It can be seen that the brake is applied automatically as soon as
disc drive base 5 is moved away from
case base 43 far enough to allow
spring 39 to rotate the
brake pad 27 into contact with the
disc drive hub 33. It can also be seen that by placing the disc drive back in the case, the
brake pad 27 automatically is moved away from
disc drive hub 33 as soon as the weight applied to
spring 39 is sufficient to cause rotation of disc
brake pad assembly 15 away from
disc drive hub 33.
The disc
brake pad assembly 15 is mounted for rotation around
pin 19 so that as the
disc brake pad 27 is brought into contact with
disc drive hub 33,
high friction surfaces 29, 31 will be parallel and thus be in full contact with each other.
While the invention has been described in reference to a single preferred embodiment, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. For example, the brake mechanism could be provided on a separate plate and the plate bolted to the base of a disc drive if desired.